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- #include "boot.h"
-
- #include <assert.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
-
- #include "cpu.h"
- #include "insn.h"
- #include "log.h"
- #include "psx.h"
-
- static const uint8_t MAGIC[0x10] = "PS-X EXE";
- static const uint8_t RESERVED[0x10] = {0};
-
- psx_header_t parse_psx_header(byte_arr_t *prgm) {
- psx_header_t header;
-
- // TODO: Convert asserts into recoverable error
- debug("Checking header struct size");
- assert(sizeof header == 0x38 - 0x10);
-
- debug("Checking program size is greater than header");
- assert(prgm->size >= 0x800);
-
- debug("Checking magic number in header");
- assert(memcmp(MAGIC, prgm->data, sizeof MAGIC) == 0);
-
- memcpy(&header, &prgm->data[sizeof MAGIC], sizeof header);
-
- debug("Checking file size in header matches program size");
- assert(header.size_file == prgm->size - 0x800);
-
- debug("Checking A34h region is zero");
- assert(memcmp(RESERVED, &prgm->data[0x38], sizeof RESERVED) == 0);
-
- return header;
- }
-
- uint32_t translate_addr(uint32_t addr) {
- if (addr >= 0xA0000000) {
- addr = addr - 0xA0000000;
- } else if (addr >= 0x80000000) {
- addr = addr - 0x80000000;
- }
-
- return addr;
- }
-
- void boot_psx_prgm(byte_arr_t *prgm) {
- debug("Parsing program header");
-
- psx_header_t header = parse_psx_header(prgm);
-
- debug("Program header");
- debug("size=%u bytes", header.size_file);
- debug("pc=%08x, gp=%08x, sp=%08x, fp=%08x", header.pc, header.gp, header.sp,
- header.fp);
- debug("data=%08x (%u bytes)", header.addr_data, header.size_data);
- debug("bss=%08x (%u bytes)", header.addr_bss, header.size_bss);
- debug("dest=%08x", header.addr_dest);
-
- cpu_t *cpu = malloc(sizeof *cpu);
-
- uint32_t start = translate_addr(header.addr_dest);
- assert(start + header.size_file < MAIN_RAM_SIZE);
- memcpy(&cpu->main_ram[start], &prgm->data[0x800], header.size_file);
-
- cpu->pc = header.pc;
- cpu->regs[REG_GP] = header.gp;
- cpu->regs[REG_SP] = header.sp;
- cpu->regs[REG_FP] = header.fp;
-
- psx_t psx = {header, cpu};
-
- while (1) {
- debug("Executing instruction at %08x", psx.cpu->pc);
-
- const uint32_t insn = cpu_read32(cpu, psx.cpu->pc);
- insn_execute(cpu, insn);
-
- psx.cpu->pc += 4;
- }
- }
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